162 IX. A8PLENIUM. 
with other tender kinds, beneath a hand-glass kept closed 
in the greenhouse. 
5. Aspleiiium Tricliomancs, Linnaeus. Common 
Spleenwort __ Fronds linear pinnate ; pumas roundish-ob- 
long, crenated,' stalked ; rachis not winged, ebeneous 
throughout. 
ASPLKNIUM TRICHOMANES, Linnams: Sm. Ens. Fl. iv., 292 : 
Eng. Bot576: Bab. Man. 414: Hook and Arn. Fl. 573 : Newra. 
285: Florigr. Brit, iv., 73: Franc. 46. ASPLENICM TRICHOMA- 
Schkuhr. PHYLLITIS ROTCNDIFOLIA, Moench. 
/3 incisum : pinnae deeply pinnatifid, with narrow in- 
ciso-serrate segments ; barren. 
The Common Spleenwort forms a dense tufted caudex, 
whose numerous wiry roots insinuate themselves in the 
crevices of the rocks and old buildings on which it esta- 
blishes itself. The fronds are terminal, adherent, ever- 
green, the young ones appearing about May, numerous, 
narrow linear, simply pinnate, and from three inches to a 
foot in length. The stipes is very short, smooth, shining, 
purplish black, which colour is continued along the 
shining rachis. The pinnae are numerous, about three 
lines long, opposite or alternate, stalked, roundish oblong, 
unequally wedge-shaped at the base, dark green, nearly 
entire on the margin, or usually more or less deeply cre- 
nated. In the variety incisum they are deeply but irre- 
gularly pinnatifid with linear-serrated segments. When 
the fronds become aged the pinnae are readily detached, 
and they eventually fall off like the leaves of a deciduous 
plant, leaving the persistent rachis quite denuded. The 
pinnae are usually quite distinct, but occasionally crowded ; 
each has a distinct mid-vein, from which proceed alter- 
nate venules, which are forked near the base, the anterior 
branch bearing the sorus just beyond the fork, and both 
terminating within the margin. The linear sori are each 
covered by a thin pale-coloured membranous indusium of 
